Method for extracting metals from concentrated sulphurated minerals containing metals by direct reduction with regeneration and recycling of the reducing agent, iron, and of the flux, sodium carbonate

ABSTRACT

A method is disclosed for extracting metals from concentrated sulphurated minerals containing metals by direct reduction with regeneration and recycling of the reducing agent, iron, and of the flux, sodium carbonate. It is a combination of pyrometallurgical and hydrometallurgical processes which differ from the conventional processes. They do not require previous toasting of the concentrated sulphurated minerals and are technically and economically more advantageous than the presently used processes, since they directly reduce to zero the positive oxidation state of the metal, using a single reactor for extracting the metal, regenerating and recycling the metallurgical feed materials in complementary processes, the kinetics of the chemical reactions being characterised by high speed, without generating any slags or pollutant gases. The metals can be extracted at a reduced cost and in an environmentally sustainable manner

TECHNICAL FIELD

The technical field relevant to apply the developed invention is miningand metallurgy, since it allows extracting ferrous and non-ferrousmetals from sulphurated minerals bearing them by applying an improveddirect reduction process, with no emissions of sulphur dioxide andwithout producing slag, which is commonly produced by conventionalpyrometallurgical plants, thus minimizing environmental pollution. Inaddition, through the proposed regeneration and recycling of iron asreducing agent and sodium carbonate as flux, the operating costs of theprocess are substantially reduced.

STATE OF THE ART (OR BACKGROUND OF INVENTION)

According to Aranguren F & Mallol A. (1), several metallurgicalreduction processes were known and applied for some time in metalextraction activities. Among them, the reduction of iron oxide minerals(mainly, hematite and magnetite) stands out for its relevance, since itallows to obtain pig iron or direct-reduced iron, metallurgical productsfrom which steel can be obtained, depending on the technique applied. Inthese cases, coal or metallurgical coke and/or carbon monoxide and/orhydrogen gas and/or natural gas are required as reducing agents;limestone and dolomite are required as alkaline fluxes, where, at thesame time as the main process occurs, the reduction of other elementstakes place in the same reactor, elements such as silicon, titanium,manganese, chromium, vanadium, among others, always from its oxidizedcompounds. The following are established as essential chemical reactionsin the reduction process applied to oxidized iron minerals:

3 Fe₂O₃+CO→2 Fe₃O₄+CO₂

Fe₃O₄+CO→3 FeO+CO₂

FeO+CO→Fe+CO₂

Similarly, as indicated by Aranguren & Mallol (2), in 1620 the firstfurnace for iron minerals processing was built in the United States ofAmerica. Later, during several centuries and until the creation ofcomprehensive plants, which included the production of pig iron andmetallurgical coke, the iron and steel industry commonly used producergas as fuel, which performed a dual function, both as heating agent andreducing agent. Producer gas was produced by total gasification of asolid fuel, such as bituminous coal, anthracite, lignite, or the samecoke, being able to produce the gasification with air alone, air andwater vapor, or also with oxygen and water vapor. The fundamentalreactions that occur in a gas-powered reactor are shown below:

C+O₂→CO₂

C+CO₂→2 CO

C+H₂O→CO+H₂

C+2 H₂O→CO₂+2 H₂

CO+H₂O→CO₂+H₂

2 C+2 H₂O→CH₄+2 CO

Improving the already known reduction process of iron minerals and usingcarbon monoxide as reducing agent, in 1918 Wieber (3) proposed thatgases resulting from iron minerals reduction, mainly carbon dioxide withresidual carbon monoxide used as reducing agent, to be conducted toanother reactor where coal combustion shall occur. This would generatemore carbon monoxide from the same recycled carbon dioxide and fromcoal, reducing the consumption of the latter.

Given that the above-mentioned improved process requires the use, to anoticeable extent, of hydrogen gas as a reducing agent due to itsgreater heating power, the presence of hydrogen gas in the percentagecomposition of reducing gases should correspond to a range between 20%and 35%, which can be achieved if natural gas is used in a complementarymanner, with a reaction to water vapor at high temperatures of:

CH₄+H₂O→3 H₂+CO

being feasible to reduce iron oxide minerals with hydrogen gas using thefollowing fundamental reactions:

3 Fe₂O₃+H₂→2 Fe₃O₄+H₂O

Fe₃O₄+H₂→3 FeO+H₂O

FeO+H₂→Fe+H₂O

On the other hand, the conventional techniques currently used to extractnon-ferrous common metals (lead, copper, zinc, antimony, etc.) fromtheir sulphurated minerals consist of toasting them to obtain oxidizedcompounds of the above-mentioned metals to, subsequently, applypyrometallurgical processes to extract lead, copper, zinc, antimony,etc.; or, alternatively, hydro-electrometallurgical processes, as in thecase of zinc extraction, being the following reactions fundamental inthe pyrometallurgical extraction of non-ferrous common metals (4):

2 PbS+3 O₂⇄2 PbO+2 SO₂

2 PbO+C⇄2 Pb+CO₂

2 Cu₂S+3 O₂⇄2 Cu₂O+2 SO₂

2 Cu₂O+C⇄4 Cu+CO₂

2 ZnS+3 O₂⇄2 ZnO+2 SO₂

2 ZnO+C⇄2 Zn+CO₂

2 Sb₂S₃+9 O₂⇄2 Sb₂O₃+6 SO₂

2 Sb₂O₃+Sb₂S₃⇄6 Sb+3 SO₂

One of the characteristics of the plants implementing these latestprocesses is the large amount of emissions of sulphur dioxide theygenerate, forcing them to install expensive sulphuric acid manufacturingplants to minimize environmental pollution, as well as great amounts ofslag, which are stockpiled near the metallurgical plants, polluting theenvironment in the area of influence.

In the same way, it is also known that coal gas (by-product ofblast-furnace coke furnaces) contains hydrogen sulphide gas, which isone of the components that should be removed before its usage. Analternative is to pass the hydrogen sulphide gas through a mass ofhydrated iron oxide to obtain the following reaction (5):

Fe₂(OH)₆+3 H₂S⇄Fe₂S₃+6 H₂O

therefore, when the mass of hydrated iron oxide is saturated withsulphur, the compounds generated are aerated, obtaining not onlyelemental sulphur (S), but also the regeneration of hydrated iron oxidedue to the following reaction caused by the presence of oxygen andwater:

Fe₂S₃+3 H₂O+3/2O₂⇄Fe₂(OH)₆+3 S

It is known that only in 1823 the first plant of sodium carbonateproduction on an industrial scale was established in England, applyingthe process conceived by Nicolas Leblanc (6), which was used up to 1885,approximately. The following are the main chemical reactions of theabove-mentioned process:

NaCl+H₂SO₄→NaHSO₄+HCl

NaCl+NaHSO₄→Na₂SO₄+HCl

Na₂SO₄+2 C→Na₂S+2 CO₂

Na₂S+CaCO₃→Na₂CO₃+CaS

In 1861, Ernest Solvay (7) developed the process named after him, whichquickly became the leading process to produce sodium carbonateworldwide. The first industrial plant that applied this process wassettled in Belgium in 1865. Later, in 1874, another plant wasestablished in England and, in 1882, the largest plant at the time wasimplemented in the United States of America, which continues to operatenowadays. Then, in 1988, the world largest sodium carbonate industrialproduction plant was settled in France and used the Solvay Process,which has the following main chemical reactions:

CaCO₃→CaO+CO₂

CaO+H₂O→Ca(OH)₂

NH₃+CO₂+H₂O+NaCl→NaHCO₃+NH₄Cl

2 NaHCO₃→Na₂CO₃+H₂O+CO₂

Ca(OH)₂+2 NH₄Cl→2 H₂O+CaCl₂+2 NH₃

In Peru, since 1955 (8), studies analyzing the possibility ofimplementing a sodium carbonate plant were carried out. However, it wasin 1978 (9) that the implementation of a sodium carbonate plant wasenvisaged, and then became effective and started to operate in 1988(10); this technology was known as the Soda—Carbon Dioxide Gas Process,which is based on the following chemical reaction:

2 NaOH+CO₂→Na₂CO₃+H₂O

DESCRIPTION OF INVENTION

The technological innovation developed allows extracting, in addition toiron, metals such as, but not limited to, lead, silver, zinc, copper,molybdenum, antimony, arsenic, with or without associated iron, and withgold that could be hosted as inclusion in certain cases, fromsulphurated minerals containing them. For this purpose, an improveddirect reduction process is applied to the metals to be extracted, whichis achieved without sulphur dioxide emissions nor producing slagscommonly generated by conventional pyrometallurgical plants, thusminimizing environmental pollution. In addition, through the proposedregeneration and recycling of iron as reducing agent and sodiumcarbonate as flux, the operating costs of the process are substantiallyreduced.

This technology can be also applied to the remediation of tailingsdeposits containing various ferrous and non-ferrous metal sulphides.Currently, the metallurgical mining matrix worldwide states thatconcentration plants only recover, through a selective flotationprocess, metallic sulphides with commercial value, such as argentiferousgalena: PbS bearing Ag, chalcopyrite: CuFeS₂ bearing Au, and sphalerite:ZnS, leaving great amounts of iron sulphides in the tailings, such aspyrite, pyrrhotite, and arsenopyrite, which are depressed in flotationcells together with non-metallic minerals extracted from mine, mainlyquartz (SiO₂) and other silicates, which are stockpiled in tailingsdeposits under inadequate conditions in most cases. This is one of themain reasons the abovementioned tailings deposits are very likely togenerate pollutants such as arsenical and acidic water in rainy seasons,due to the high amount of arsenic and iron sulphides they contain.

The remediation of the tailings of these concentration plants registeredas mining environmental liabilities would only be feasible if we takeeconomic advantage of most mineral species existing in said tailings,trying to mainly recover the metallic mineral species disposed, such aspyrite, pyrrhotite, and arsenopyrite, not only because these minerals,part of the main pollutant species, can have important values of goldand silver, but also because they can serve as raw material forobtaining metallic iron by using this low-cost technological innovationwith minimal environmental impact; thus, iron becomes a metallurgicalproduct with significant commercial value from which steel can beobtained for the construction and metal-mechanic industries.

In addition, other residual metallic sulphides of commercial value mightbe also recovered through selective flotation, provided that these arecontained in the tailings deposits. It is important to take them intoaccount, not only because that would help to increase the income fromthe sale of non-ferrous metals to be obtained, which would be extractedfrom sulphurated minerals bearing them through the technologicalinnovation developed, but also because the application of this inventionwould finally allow to obtain truly clean solid waste that might be usedin the construction industry as an aggregate (fine sand) or raw materialfor white bricks manufacturing.

In the smelting furnace considered for this process, the concentratedsulphurated minerals, bearing the metal or metals to be extracted, aresmelted, as the case may be. For this purpose, iron is used as reducingagent and sodium carbonate as flux, resulting in smelted or powderedmetal or metals, depending on their physical properties, a slag ofcontrolled composition formed by ferrous oxide and sodium sulphide, andgaseous emissions of carbon dioxide. In order to have an effectivecontrol of the slag composition, which is essential to regenerate andrecycling the reducing agent and flux, general reactions are establishedfor the cases below, considering the following general definitions:

-   -   Fe is a reactive element with an oxidation number of zero; when        added to the main reactor, it acts as a reducing agent or        facilitator for the atomic exchange between sulphur and sodium,        where applicable.    -   Na₂CO₃ is a reactive chemical compound known as sodium        carbonate, which is added to the main reactor as flux.    -   Na₂S is one of the slag components, known as sodium sulphide,        obtained from the general chemical reaction; it is highly        water-soluble.    -   FeO is another slag component known as ferrous oxide, obtained        from the general chemical reaction; it is water insoluble.    -   CO₂ is the gaseous effluent known as carbon dioxide, obtained        from the general chemical reaction.

-   a. For single-metal non-ferrous sulphurated minerals:

M_(x)S_(y)+y Fe+y Na₂CO₃→x M+y Na₂S+y FeO+y CO₂

-   -   Where:    -   M is the non-ferrous metal to be extracted, such as, but not        limited to, lead, silver, zinc, copper, molybdenum, antimony.    -   M_(x)S_(y) is the chemical formula for the sulphurated mineral        from which the M metal is going to be extracted.    -   x and y indicate the number of M metal atoms existing in        M_(x)S_(y) to be extracted, and those of sulphur, respectively,        existing in M_(x)S_(y); the stoichiometric coefficients of the        remaining reactants and those of the products obtained in the        process, depend on its values.

-   b. For single-metal ferrous sulphurated minerals:

M_(x)Fe_(y)S_(z)+(z−y)Fe+z Na₂CO₃→x M+z Na₂S+z FeO+z CO₂

-   -   Where:    -   M is the non-ferrous metal to be extracted, such as, but not        limited to, copper, arsenic, lead, zinc.    -   M_(x)Fe_(y)S_(z) is the chemical formula established for the        ferrous sulphurated mineral from which the M metal is going to        be extracted.    -   x, y, z refers to the number of M metal atoms existing in        M_(x)Fe_(y)S_(z) to be extracted, those of iron and sulphur,        respectively; the stoichiometric coefficients of the remaining        reactants and those of the products obtained in the process,        depend on its values.

-   c. For single-metal sulphurated minerals, ferrous and/or    non-ferrous, with Gold and/or Silver:

M_(x)Fe_(y)S_(z)+(Au,Ag)_(m)+n Pb+(z−y)Fe+z Na₂CO₃→→x M+m(Au,Ag)+n Pb+zNa₂S+z FeO+z CO₂

-   -   Where:    -   M is the non-ferrous metal to be extracted, such as, but not        limited to, copper, arsenic, lead, zinc.    -   M_(x)Fe_(y)S_(z) is the chemical formula established for the        ferrous and non-ferrous sulphurated mineral (for y=0) from which        the M metal and other precious metals associated will be        extracted.    -   x, y, z indicate the number of M metal atoms to be extracted,        those of iron and sulphur, respectively, existing in        M_(x)Fe_(y)S_(z); the stoichiometric coefficients of the other        reactants and those of the products obtained in the process,        depend on its values.    -   (Au,Ag)_(m) represent the inclusions of Gold (Au), Silver (Ag)        and Electrum (Au/Ag) that are shown within the M_(x)Fe_(y)S_(z)        mineral matrix in an “m” number.    -   Pb represents the Lead metal, which in “n” quantity is added        along with reactants, in order to be the final bearer of Gold        and Silver.

-   d. For combinations of several single-metal sulphurated minerals,    ferrous and/or non-ferrous:

[(M1)_(a)Fe_(b)S_(c)+(c−b)Fe+c Na₂CO₃]+[(M2)_(x)Fe_(y)S_(z)+(z−y)Fe+zNa₂CO₃]→→a (M1)+x (M2)+(c+z)Na₂S+(c+z)FeO+(c+z) CO₂

-   -   which expressed in another way is equal to:

(M1)_(a)Fe_(b)S_(c)+(M2)_(x)Fe_(y)S_(z)+[(c−b)+(z−y)]Fe+(c+z) Na₂CO₃→→a(M1)+x (M2)+(c+z)Na₂S+(c+z)FeO+(c+z)CO₂

-   -   Where:    -   M1 and M2 are the non-ferrous metals to be extracted, such as,        but not limited to, copper, arsenic.    -   (M1)_(a)Fe_(b)S_(c) and (M2)_(x)Fe_(y)S_(z) are the chemical        formulas established for the ferrous and/or non-ferrous        sulphurated minerals (for y =0) from which non-ferrous metals M1        and M2 will be extracted.    -   Subscripts a, b, c, as well as x, y, z indicate the atoms        numbers involving both, metals M1 and M2, as well as the Iron        and Sulphur existing in (M1)_(a)Fe_(b)S_(c) and        (M2)_(x)Fe_(y)S_(z), respectively. The stoichiometric        coefficients of the remaining reactants (reducing agent and        flux) and those of the products obtained in the process (molten        metals, slag, and gaseous effluent), depend on its values.

-   e. For bimetallic sulphurated minerals, ferrous and/or non-ferrous:

(M1)_(a)(M2)_(b)Fe_(y)S_(z)+(z−y)Fe+z Na₂CO₃→a(M1) b(M2)+z Na₂S+z FeO+zCO₂

-   -   Where:    -   M1 and M2 are the non-ferrous metals to be extracted, such as,        but not limited to, antimony, zinc, copper, silver, arsenic,        cobalt.    -   (M1)_(a)(M2)_(b)Fe_(y)S_(z) is the chemical formula established        for the ferrous and non-ferrous sulphurated mineral (for y=0)        from which non-ferrous metals M1 and M2 will be extracted.    -   Subscripts a, b, as well as y, z, indicate the atoms numbers        involving both, metals M1 and M2, as well as the Iron and        Sulphur, respectively, existing in (M1)_(a)(M2)_(b)Fe_(y)S_(z).        The stoichiometric coefficients of the remaining reactants        (reducing agent and flux) and those of the products obtained in        the process (molten metals, slag, and gaseous effluent), depend        on its values.

-   f. For combinations of bimetallic sulphurated minerals, ferrous    and/or non-ferrous:

[(M1)_(a)(M2)_(b)Fe_(c)S_(d)+(M3)_(w)(M4)_(x)Fe_(y)S_(z)+[(d−c)+(z−y)]Fe+(d+z)Na₂CO₃]→→a(M1)+b (M2)+w (M3) x (M4)+(d+z)Na₂S+(d+z)FeO+(d+z)CO₂

-   -   Where:    -   M1, M2, M3 and M4 are the non-ferrous metals to be extracted,        such as, but not limited to, antimony, zinc, copper, silver,        arsenic, cobalt.    -   (M1)_(a)(M2)_(b)Fe_(c)S_(d) and (M3)_(w)(M4)_(x)Fe_(y)S_(z) are        the chemical formulas established for the ferrous and        non-ferrous sulphurated minerals from which non-ferrous metals        M1, M2, M3, and M4 will be extracted.    -   Subscripts a, b, c, d, as well as w, x, y, z, indicate the atoms        numbers involving both, metals M1, M2, M3, and M4, as well as        the Iron and Sulphur, respectively, existing in        (M1)_(a)(M2)_(b)Fe_(c)S_(d) and (M3)_(w)(M4)_(x)Fe_(y)S_(z). The        stoichiometric coefficients of the remaining reactants (reducing        agent and flux) and those of the products obtained through the        process (molten metals, slag, and gaseous effluent), depend on        its values.

It should be noted that the above-mentioned stoichiometric formulationis valid even when some (or all) of the following cases occur:

-   -   When chemical formulas of bimetallic sulphurated minerals        contain a non-ferrous metal in common, i.e., when (M1, M2) is        partially equal to (M3, M4).    -   When in the combination of bimetallic sulphurated minerals, one        of the sulphurated minerals is ferrous and the other sulphurated        mineral is non-ferrous.

In this sense, the simultaneous presence of both cases mentioned above,would have the following stoichiometric formulation, where M4=M2, andy=0:

[(M1)_(a)(M2)_(b)Fe_(c)S_(d)+(M3)_(w)(M2)_(x)S_(z)+[(d−c)+(z)]Fe+(d+z)Na₂CO₃]→→a(M1)+(b+x) (M2)+w (M3)+(d+z) Na₂S+(d+z)FeO+(d+z) CO₂

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1: Metallurgical Extraction Process

-   -   1 a Ferrous and Non-ferrous Concentrated sulphurated minerals,        with Gold inclusions where applicable.    -   1 b Reducing agent (Fe)    -   1 c Flux (Na₂CO₃)    -   1 d Slag (FeO and Na₂S)    -   1 e Molten Metals    -   1 f Carbon Dioxide Gas to recycling CO₂    -   1 g Smelting furnace

FIG. 2: Dissolving and Filtering Slag Components

-   -   2 a Water (H₂O)    -   2 b Slag (FeO and Na₂S)    -   2 c Sintering (FeO)    -   2 d Filtered Solution (Na₂S +H₂O)    -   2 e Dissolving and Filtering

FIG. 3: Regeneration of Sodium Carbonate for Recycling

-   -   3 a Hydrogen Sulphurated Gas or Hydrogen Sulphide (H₂S)    -   3 b Filtered Solution (Na₂S+H₂O)    -   3 c Recycled Carbon Dioxide Gas (CO₂)    -   3 d Oversaturated Solution of Sodium Carbonate (Na₂CO₃+H₂O)    -   3 e Sodium Carbonate (Na₂CO₃) or regenerated Flux    -   3 f Smelting Furnace for Concentrates    -   3 g Water (H₂O)    -   3 h Solutions Reactor (Na₂S+H₂O+Na₂CO₃): Oversaturated and        Filtered Solutions

FIG. 4: Removal of Hydrogen sulphide Gas and extraction of elementalSulphur

-   -   4 a Water (H₂O)    -   4 b Air (O₂)    -   4 c Hydrogen Sulphurated Gas (H₂S)    -   4 d Solid/Gas Reactor (Hydrated Iron Oxide Fe₂(OH)₆ and        Sulphurated Hydrogen H₂S)    -   4 e Regenerated Hydrated Iron Oxide (Fe₂(OH)₆)    -   4 f Elemental Sulphur (S)    -   4 g Ferric Sulphide with Water (Fe₂S₃+H₂O)

FIG. 5: Sintering:

-   -   5 a Ferrous Oxide (FeO) Residues    -   5 b Ferrous Oxide (FeO) Pellets    -   5 c Sintering Furnace

FIG. 6: Generation of Reducing Gases

-   -   6 a Reducing Gases (CO+H₂)    -   6 b Air oxygen and Water Vapor (O₂ and H₂O)    -   6 c Coal (C) or Metallurgical Coke (Desulphurized C) or Natural        Gas (CH₄)    -   6 d Recycled gases (CO₂ and CO)    -   6 e Combustion Furnace

FIG. 7: Regeneration of Iron as Reducing Agent for Recycling

-   -   7 a Reducing Gases (CO+H₂)    -   7 b Metallic iron (Fe)    -   7 c Ferrous Oxide Pellets (FeO)    -   7 d Reduction Furnace

FIG. 8: Comprehensive Process for Extracting Ferrous and Non-FerrousMetals, and Gold as an Inclusion where Applicable, Through the Smeltingof Concentrated Sulphurated Minerals Bearing them, with the Regenerationand Recycling of Metallurgical Inputs

-   -   8 a Metal-bearing concentrated sulphurated minerals, with Gold        inclusions where applicable    -   8 b Recycled Iron (Fe) as Reducing Agent    -   8 c Recycled Sodium Carbonate (Na₂CO₃) as Flux    -   8 d Ferrous Oxide and Sodium Sulphide (FeO+Na₂S) as Slags    -   8 e Molten Metals    -   8 f Carbon Dioxide Gas (CO₂) to recycle    -   8 g Concentrates Smelting Furnace    -   8 h Water (H₂O)    -   8 i Dissolving and Filtering    -   8 j Ferrous Oxide (FeO) Residues    -   8 k Solutions Reactor (Na₂S+H₂O)    -   8 l Water (H₂O)    -   8 m Prepared Solution (Na₂CO₃+H₂O)    -   8 n Regenerated Sodium Carbonate (Na₂CO₃)    -   8 ñ Hydrogen sulphide Gas (H₂S)

-   8 o Sintering Furnace    -   8 p Ferrous Oxide (FeO) Pellets    -   8 q Metallic Iron or Direct-Reduced Iron (Fe)    -   8 r Recycled Gases (CO₂ and CO)    -   8 s Reduction Furnace    -   8 t Combustion Furnace    -   8 u Coal (C) or Metallurgical Coke (Desulphurized C) or Natural        Gas (CH₄)    -   8 v Air and water vapor (O₂ and H₂O)    -   8 w Reducing Gases (CO and H₂)    -   8 x Solid/Gas Reactor: Hydrated Iron Oxide (Fe₂(OH)₆) and        Sulphurated Hydrogen (H₂S)    -   8 y Ferric Sulphide+Water (Fe₂S₃+H₂O)    -   8 z Elemental sulphur (S)    -   8 aa Hydrated Iron Oxide (Fe₂(OH)₆)    -   8 ab Water (H₂O)    -   8 ac Air (O₂)

DETAILED DESCRIPTION OF DRAWINGS

The present invention includes a new technological process of sevenstages, which are schematized in detail in the following diagrams.

-   -   FIG. 1: It shows the metallurgical process diagram for the        extraction of metals, such as, but not limited to, lead, silver,        zinc, copper, molybdenum, antimony, arsenic, iron, gold        included, where applicable, through smelting of non-ferrous        and/or ferrous concentrated sulphurated minerals bearing them (1        a). This process is carried out in a smelting furnace (1 g), by        adding 3 reactants: Non-Ferrous and/or Ferrous Mineral        Concentrate, with gold as an inclusion, as the case may be (1        a), Iron or Fe as reducing agent (1 b) and Sodium Carbonate or        Na₂CO₃ as flux (1 c) to later obtain, as a result of the        metallurgical process, the molten metal or metals formed by the        metallic elements contained in the non-ferrous and/or ferrous        mineral concentrates, including gold (1 e), as the case may be,        a slag made up of Ferrous Oxide or FeO, and Sodium Sulphide or        Na₂S (1 d) and gaseous effluent of Carbon Dioxide or CO2 (1 f),        which will be captured and delivered to recycling.    -   FIG. 2: It shows a diagram of the dissolving process of a        component of slag generated in the smelting furnace of        concentrated sulphurated and/or non sulphurated minerals,        mentioned in the previous stage, where the slag, formed by        Ferrous Oxide or FeO and Sodium Sulphide or Na₂S (2 b), with        Water or H₂O (2 a), are added to a Dissolving Reactor with        subsequent filtering (2 e), obtaining two products: a filtered        solution of Sodium Sulphide or Na₂S and Water or H₂O (2 d), and        a solid residue of Ferrous Oxide or FeO that, previously        agglomerated, will be sintered (2 c).    -   FIG. 3: It shows a diagram of the regeneration process of sodium        carbonate as flux. This process takes place in a Solutions        Reactor (3 h) where we add the filtered solution of sodium        sulphide (Na₂S+H₂O) (3 b), an oversaturated solution of sodium        carbonate and water (Na₂CO₃+H₂O) (3 d), blowing the Carbon        Dioxide gas or CO₂ recycled (3 c) into this mix, to then obtain        3 products: Hydrogen sulphide Gas or H₂S (3 a) that will be        captured for its subsequent processing, Water or H₂O (3 g), and        regenerated Sodium Carbonate (Na₂CO₃) (3 e), which will be        recycled to the process, most of it will be used in the smelting        furnace of concentrates (3 f), and other small part will be used        in the preparation of oversaturated sodium carbonate solution        with water (Na₂CO₃+H₂O) (3 d).    -   FIG. 4: It shows a diagram of the process of Hydrogen sulphide        Gas removal and Sulphur extraction. For this purpose, the        Hydrogen sulphide Gas or H₂S (4 c) is blown into a Solid/Gas        Reactor (4 d) containing crystals of Hydrated Iron Oxide or        Fe₂(OH)₆ (4 e). Both compounds react producing Ferric Sulphide        or Fe₂S₃ with Water or H₂O (4 g). Then, air containing Oxygen or        O₂ (4 b) is added to these products, producing a reaction that        generates 3 products: Water or H₂O (4 a), elemental Sulphur or S        (4 f), and hydrated Iron Oxide or Fe₂(OH)₆ (4 e), which will be        recycled to the same process.    -   FIG. 5: This diagram represents the Sintering process for solid        residues of Ferrous Oxide or FeO (5 a), which were obtained from        dissolving a slag component and its subsequent filtering. Prior        to sintering, the above-mentioned solid residues are        agglomerated (5 b) and ready to be subjected to heating with        controlled temperature in a Sintering Furnace (5 c), where they        are compacted and then harden with the subsequent cooling,        forming the “Pellets”, which are resistant to compression,        required to regenerate Iron as reducing agent.    -   FIG. 6: This diagram represents the Coal, Metallurgical Coke or        Natural Gas Combustion process for the generation of reducing        gases, Carbon Monoxide and Hydrogen, which are obtained in a        Combustion Furnace (6 e) by adding coal or metallurgical coke or        natural gas (6 c), air and water vapor (O₂ and H₂O) (6 b) and        Carbon Dioxide or CO₂ recycled gases (residual from the process        of iron reduction) and Carbon Monoxide or CO (residual from the        non-reacting reducing gas), water vapor or H₂O and Natural Gas        or CH₄ if the latter was used (6 d), to again obtain the        reducing gases, Carbon Monoxide (CO) and Hydrogen (H2) (6 a)        from the Combustion Furnace.    -   FIG. 7: The diagram shows the reducing agent regeneration        process through the reduction of the iron hosted in Ferrous        Oxide. For this purpose, the reducing gases, Carbon Monoxide and        Hydrogen, are used. In this process, the Pellets of Ferrous        Oxide or FeO (7 c) are fed into the Reduction Furnace (7 d) and        then the Reducing Gases, Carbon Monoxide or CO and Hydrogen or        H₂ (7 a) are injected, thus obtaining metallic Iron or Fe (7 b)        by reducing the Ferrous Oxide oxidation from +2 to zero. In this        way, the regeneration of the reducing agent is achieved for its        recycling to the concentrated sulphurated minerals smelting        furnace, where non-ferrous metals are extracted, stating that,        along with the gaseous effluent Carbon Dioxide or CO₂ (7 e), a        residual reducing gas Carbon Monoxide or CO, which did not react        to the process, is also produced.    -   FIG. 8: Finally, through the sequential integration of all the        figures above, a new Metallurgical Process is established for        the extraction of non-ferrous and ferrous metals from        sulphurated minerals bearing them (8 a), improving the state of        the art, since this means that the application of the        pyrometallurgical process of direct reduction is carried out        with reduced operating costs and minimal environmental        pollution, as a result of regeneration and recycling of Iron or        Fe (8 b) as reducing agent and Sodium Carbonate or Na₂Co₃ (8 c)        as flux.

PREFERRED EXAMPLES (OR PREFERRED EMBODIMENT OF THE INVENTION)

Preferred examples of the real applicability of the TechnologicalInnovation described in the previous points:

1. First Preferred Example Extraction of Copper and Gold, or OtherMetals Such as Cobalt, Arsenic and Iron, as Applicable, by SmeltingConcentrates of Sulphurated Minerals Containing Them, Such asChalcopyrite, Calcosine, Bornite, Enargite, Carrotite and Tenantite.

The extraction of Copper, Gold as an inclusion, and other metals fromthe sulphurated minerals that contain them (Chalcopyrite (CuFeS₂)),Chalcocite: Cu₂S, Bornite: Cu₅FeS₄, Enargite: Cu₃AsS₄, Carrotite:CuCo₂S₄ and Tenantite: Cu₁₂As₄S₁₃) to which they can be associated, isbased on using appropriate amounts of both the reducing agent Iron (Fe),as well as the flux Sodium Carbonate (Na₂CO₃), and the products of thechemical reaction that occurs between the aforementioned reactants arethe following: Metallic Copper (Cu) melted with Gold, if it was aninclusion, a slag constituted by Ferrous Oxide (FeO) and Sodium Sulphide(Na₂S), and gaseous emissions of Carbon Dioxide (CO₂).

In the case of the Chalcopyrite, the chemical formula established forthis sulphurated mineral is used: CuFeS₂, from which the Copper (Cu) isextracted, specifying that the smelting of the concentrates of thissulphurated mineral together with Iron (Fe) as a reducing agent andSodium Carbonate (Na2CO3) as a flux should be carried out consideringthe appropriate stoichiometric quantities, not only for the directreduction of Copper (Cu), but also to control the composition of theslag to be produced, so that the regeneration and recycling of both thereducing agent Iron (Fe) and the flux of Sodium Carbonate (Na₂CO₃) ispossible in the following sub-processes, which implies that the slag ofthe direct reduction process of Copper (Cu) should not be composed ofthree or more compounds, but only two, and it is necessary that one ofthem is soluble in Water, that is, it must be composed by the insolublecompound Ferrous Oxide (FeO) and by the highly soluble compound SodiumSulphide (Na₂S), so that the products of the chemical reaction in thereactor are high density molten Copper (Cu), containing Gold if it wasan inclusion, an alkaline and low density fluid slag, and the gaseouseffluent Carbon Dioxide (CO₂), according to the following reaction:

CuFeS₂+Au+Fe+2 Na₂CO₃→Cu+Au+2 Na₂S+2 FeO+2 CO₂

It is specified that the amount of flux that must be added to thereactor should be appropriate so that Ferrous Sulphide (FeS) does notappear in the slag. According to chemical thermodynamics, the reactionbegins to occur from 1100° C., and should preferably be completed at1350° C.

Due to the reaction mechanisms involved in the process of directreduction of Copper from the sulphur minerals that contain it(Chalcopyrite, Chalcocite, Bornite, Enargite, Carrotite and Tenantite),the number of gram-atoms of Iron (Fe), or its equivalent in weight,which will have to be considered as a reducing agent reactant in theaforementioned process, is directly related to the number of Sulphur (S)atoms contained in the sulphide copper mineral, and the gram-atoms ofIron, or its equivalent in weight, that are contained in the coppersulphurated minerals such as Chalcopyrite and Bornite must be reduced tothe resulting amount, if applicable. On the other hand, the number ofmoles of Sodium Carbonate (Na₂CO₃), or its equivalent in weight, whichmust be considered as a reactant flux in the aforementioned process, isalso directly related to the amount of Sulphur atoms existing in thechemical formula of Chalcopyrite or other copper-containing sulphuratedminerals such as Chalcocite, Bornite, Enargite, Carrotite and Tenantite,according to the corresponding chemical reactions specified that follow:

Cu₂S+Fe+Na₂CO₃→2 Cu+FeO+Na₂S+CO₂

Cu₅FeS₄+3 Fe+4 Na₂CO₃→5 Cu+4 FeO+4 Na₂S+4 CO₂

Cu₃AsS₄+4 Fe+4 Na₂CO₃→3 Cu+As+4 FeO+4 Na₂S+4 CO₂

CuCo₂S₄+4 Fe+4 Na₂CO₃→Cu+2 Co+4 FeO +4 Na₂S+4 CO₂

Cu₁₂As₄S₁₃+13 Fe+13 12 Cu+4 As+13 FeO+13 Na₂S+13 Na₂CO₃→CO₂

2. Second Preferred Example Lead and Silver Extraction by SmeltingConcentrated Sulphurated Minerals of Lead, Such as Galena, and Silver,Such as Acanthite, Alone or Associated:

In this process, the extraction of the lead metal from the Galena (PbS),or from the sulphurated mineral that contains it, is based on theappropriate use of both Iron (Fe) as a reducing agent as well as SodiumCarbonate (Na₂CO₃) as flux, and the products of the chemical reactionthat occurs between the aforementioned reactants are the following: Castmetal lead, a slag formed by Ferrous Oxide (FeO) and Sodium Sulphide(Na₂S), and gaseous emissions of Carbon Dioxide (CO₂). In order to havean effective control during the formation of the slag, since it iscritical step, the chemical formula established for the Galena or LeadSulphide is used: PbS, a sulphurated mineral from which metal lead is tobe extracted. It should be considered that the application of theimproved direct reduction process involves the use of the reducing agentand the flux in the appropriate stoichiometric proportions, so that theregeneration and recycling of the referred metallurgical inputs arefeasible in the following processes. For this purpose, it isindispensable for the slag, at the end, to be formed not by three ormore compounds, but only by two, and one of them should be soluble inWater. In this regard, it should be pursued that the slag obtained fromthe metal lead extraction in smelting furnace only consists of theinsoluble compound Ferrous Oxide (FeO) and the water-soluble compoundSodium Sulphide (Na₂S), which requires full control of the formation ofFerrous Sulphide (FeS) in the slag, and can be achieved if the mainreaction of the direct reduction process using Iron (Fe) as a reducingagent and Sodium Carbonate (Na₂CO₃) as a flux is the following:

PbS+Fe+Na₂CO₃→Pb+Na₂S+FeO+CO₂

According to chemical thermodynamics, the aforementioned reaction beginsto occur at 950° C. and should preferably be completed by 1400° C.

Likewise, while extracting Silver from the sulphurated minerals thatcontain it, such as, without limitation, Acanthite or Ag₂S (Argentite attemperatures greater than 177° C.), proper use of both Iron (Fe) as areducing agent and Sodium Carbonate (Na₂CO₃) as a flux should beapplied, and the products of the chemical reaction between theaforementioned reactants are the following: cast metal silver, a slagformed by Ferrous Oxide (FeO) and Sodium Sulphide (Na₂S), and gaseousemissions of Carbon Dioxide (CO₂). Regarding the slag, the same criteriaand technical foundations for its conformation are applied, so it isnecessary for the chemical reaction occurring inside the furnace, wherethe sulphurated minerals concentrates are cast, to be the following:

Ag₂S+Fe+Na₂CO₃→2 Ag+Na₂S+FeO+CO₂

According to chemical thermodynamics, the aforementioned reaction beginsto occur at 775° C. and should preferably be completed by 1425° C.

However, in general, Galena (PbS) is associated with various sulphideSilver minerals such as Acanthite (Ag₂S), so that the reactants must behandled in the smelting furnace in order to carry out the followingchemical reaction:

PbS+Ag₂S+2 Fe+2Na₂CO₃→Pb+2Ag+2Na₂S+2FeO+2CO₂

It should be noted that Acanthite or Ag₂S contributes one more atom ofSulphur (S) to the reactants, which should be reflected in the amountsof the reducing agent Iron and the flux Sodium Carbonate that must beadded. According to chemical thermodynamics, the aforementioned reactionbegins at 950° C. and should preferably be completed by 1150° C.,although it was experimentally verified that the reaction occurscompletely at 950° C.

In view of the above, it is concluded that, during the process of directreduction of Lead from the sulphurated mineral containing it, the numberof moles of Sodium Carbonate (Na₂CO₃), or its equivalent in weight,which should be considered as a reactant flux in the process, isdirectly related to the sulphur atoms existing in the chemical formulaof Galena or Lead Sulphide (PbS), a mineralogical compound that containsthe metal Lead to be extracted. Likewise, the number of gram-atoms ofIron (Fe), or its equivalent in weight, that will need to be consideredas a reactive reducing agent in the process is directly related to thenumber of gram-moles of Ferrous Oxide (FeO) that will be obtained and,as it depends on the number of gram-moles of Oxygen (O₂) released assuch in the chemical reaction, it is inferred that the required amountof gram-atoms of Iron (Fe) atoms will depend on the number of moles ofSodium Carbonate (Na₂CO₃) considered as a flux and also on the number ofSulphur atoms (S) contained in the Galena or Lead Sulphide (PbS).

3. Third Preferred Example Zinc and Silver Extraction by SmeltingConcentrated Sulphurated Minerals of Zinc, Such as Sphalerite, andSilver, Such as Acanthite, Alone or Associated:

In this process, the extraction of Zinc metal from the Sphalerite (ZnS)or the sulphurated mineral that contains is done by applying theimproved direct reduction process, which is based on the proper use ofboth Iron (Fe) as a reducing agent and Sodium Carbonate (Na₂CO₃) as aflux, and the products of the chemical reaction between the reactantsare the following: metal gaseous Zinc (later liquefied by condensation),a light and fluid slag formed by Ferrous Oxide (FeO) and Sodium Sulphide(Na₂S), and gaseous emissions of Carbon Dioxide (CO₂). Given itsimportance, it is also necessary to have an effective control during theformation of the slag during the direct reduction process. To do this,once the smelting furnace is charged with the concentrated minerals ofSphalerite, the Iron (Fe) is added as a reducing agent and SodiumCarbonate (Na₂CO₃) as a flux, specifying that the use of thesemetallurgical inputs must be done in stoichiometric proportions, so thatthe regeneration and recycling of both the reducing agent and the fluxis possible from the products obtained from the chemical reaction. Thiscan be achieved if the slag is mainly formed not by three or morecompounds, but only by two, and one of them should be soluble in Water.In this regard, it should be pursued that the slag obtained from themetal Zinc extraction in the smelting furnace consists only of theinsoluble compound Ferrous Oxide (FeO) and the water-soluble compoundSodium Sulphide (Na₂S), which implies full control of the non-formationof Ferrous Sulphide (FeS) in the slag, for which it is necessary thatthe chemical reaction of the process complies with the following:

ZnS+Fe+Na₂CO₃→Zn+Na₂S+FeO+CO₂

According to chemical thermodynamics, the reaction begins at 1000° C.and is preferably completed at 1850° C.

In this sense, if Sphalerite (ZnS) is associated with sulphurated Silverminerals such as Acanthite (Ag₂S), then, the chemical reaction that willoccur in the smelting furnace is the following:

ZnS+Ag₂S+2 Fe+2Na₂CO₃→Zn+2Ag+2Na₂S+2FeO+2CO₂

It should be noted that Silver, when presented in association with thezinc sulphides in the form of Acanthite or Ag₂S, contributes one moreSulphur (S) atom to the reactants, which will affect the quantitiesrequired from the reducing agent Iron and the flux Sodium Carbonate.According to chemical thermodynamics, the reaction begins at 950° C. andshould preferably be completed at 1150° C.

In view of the above, it is concluded that, during the process of directreduction of Zinc from the sulphurated mineral containing it, the numberof moles of Sodium Carbonate (Na₂CO₃), or its equivalent in weight,which should be considered as a reactant flux during the process, isdirectly related to the existing sulphur atoms in the chemical formulaof Sphalerite (ZnS), a mineralogical compound containing the zinc metalto be extracted. Likewise, the number of gram-atoms of Iron (Fe), or itsequivalent in weight, which must be considered as a reactive reducingagent in the process, is directly related to the number of gram-moles ofFerrous Oxide (FeO) obtained as a product and, as it depends on thenumber of gram-moles of Oxygen (O₂) released as such in the chemicalreaction, it is inferred that the required gram-atoms of Iron (Fe) willdepend on the number of moles of Sodium Carbonate (Na₂CO₃) considered asa flux and also on the number of Sulphur atoms (S) contained in theSphalerite (ZnS).

4. Fourth Preferred Example Extraction of Gold, Silver and Iron bySmelting Concentrated Gold-Iron Sulphurated Minerals Such as, but NotLimited to, Pyrite, Pyrrhotite and Marcasite.

In this process, the extraction of Gold (Au), Silver (Ag) and Iron (Fe)contained in the sulphurated minerals of the latter, such as Pyrite(FeS₂), Pyrrhotite (FeS), Marcasite (FeS₂), is carried out by applyingthe improved direct reduction, using the Sodium Carbonate flux in anappropriate way and the Iron in a complementary way as a facilitator ofthe atomic exchange, which depends on the mineralogical species. In thecase of mono-sulphurated iron minerals (pyrrhotite), the iron content inthese is sufficient to cause the chemical reactions between thereactants that allow the extraction of Gold and Silver. In the case ofthe bi-sulphurated iron minerals, given that there is twice the sulphuratoms in the reactants, it will always be necessary to add thestoichiometrically necessary amount of iron as a reactant so that itacts efficiently as a facilitator of the atomic exchange in the chemicalreaction. However, for an effective extraction of this precious metals,Gold and Silver, it is necessary to introduce not only the ironsulphurated concentrates in the smelting furnace together with theadditional Sodium Carbonate and Iron flux if necessary, but also metalLead, so that it together with the precious metals Gold and Silver forma high density cast metal product that can be sieved and that, in turn,is easily separable from the other product called slag, which will be oflow density and low viscosity because it will be mainly composed ofFerrous Oxide (FeO) and Sodium Sulphide (Na₂S), which gives gaseousemissions of Carbon Dioxide (CO₂) as a third product.

Also, it is important to specify that the metal Lead, the same one thatis added to the smelting furnace together with the reactants, isobtained as a cast metal product carrying the metals Gold and Silver,which are also cast. On the other hand, in order to have an effectivecontrol during the formation the slag, it is necessary that the ironsulphide concentrate smelting, as in the case of the gold pyrites, whichis introduced in the furnace together with the additional Iron (Fe)required and the indispensable Sodium Carbonate (Na₂CO₃) as a flux, ismade considering the appropriate stoichiometric amounts of thesemetallurgical inputs, not only to obtain the maximum recoveries of Goldand Silver, but also to meet the need to have a controlled compositionof the slag to be produced, so that the regeneration and recycling ofboth the reducing agent Iron (Fe) and the flux of Sodium Carbonate(Na₂CO₃) is possible in the subsequent processes. This implies that caremust be taken so that the slag from the Gold extraction process (Au) isformed not by three or more compounds, but only by two, and one of themshould be soluble in Water, so that the three products of the chemicalreaction happening in the smelting furnace are, first of all, thehigh-density cast metal product consisting of Gold, Silver and Lead,secondly, a low density fluid slag formed by Ferrous Oxide and SodiumSulphide (FeO and Na₂S) and, finally, the gaseous effluent CarbonDioxide (CO₂), according to the following reaction:

Au+Ag₂S+Pb+FeS₂+2 Fe+3Na₂CO₃→Au+2Ag+Pb+3Na₂S+3FeO+3CO₂

According to chemical thermodynamics and considering the energy costsinvolved, the temperature range in which the reaction preferentiallyoccurs is between 775° C.-950° C. The above chemical reaction is merelyan example, since it is known that the mineralogical species containedin Silver appear in much lower quantities (Ounces/Ton) than thepercentage amounts contained in Pyrite.

It should be noted that Silver is associated with iron sulphides in theform of Acanthite Ag₂S (Argentite above 177° C.) and, therefore,contributes one more atom of Sulphur (S) to the reactants, which willaffect the quantities required of the reducing agent Iron and the fluxSodium Carbonate. Likewise, the amount of flux that must be added to thereactor must be correct so that Ferrous Sulphide does not form in theslag (FeS).

In view of the above, it can be inferred that, in case no silversulphurated mineral is associated with Pyrite (FeS₂), and if the latteris only gold pyrite, then the following chemical reaction will takeplace in the smelting furnace:

Au+Pb+FeS₂+Fe+2Na₂CO₃→Au+Pb+2Na₂S+2FeO+2CO₂

In accordance with chemical thermodynamics and considering the energycosts, the temperature range in which the reaction preferentially occursis between 750° C.-950° C., and it should be specified that the goldextraction process from gold pyrite or Iron disulphide (FeS₂) ischaracterized by, on the one hand, the number of gram-atoms of iron(Fe), or its equivalent in weight, which will need to be considered as areactive reducing agent in the process, is directly related to thenumber of atoms of Sulphur (S) contained in the Pyrite or Irondisulphide (FeS₂), exceptionally the gram-atoms of Iron or itsequivalent in weight that are contained in the gold pyrite must bededucted in this calculation. And, on the other hand, the number ofmoles of Sodium Carbonate (Na₂CO₃), or its equivalent in weight, thatshould be considered as a reactant flux in the Gold extraction processis also directly related to the amount of existing Sulphur atoms in thechemical formula of Pyrite or Iron Disulphide (FeS₂).

It should be noted that, by means of complementary metallurgicalprocesses such as the dissolution of part of the slag (of the solubleSodium Sulphide or Na₂S), the filtering of the solid waste (FeO), theagglomeration and sintering of the Ferrous Oxide (FeO) pellets and thereduction of Iron from the FeO pellets using reducing gases (CarbonMonoxide and Hydrogen), the metal iron is finally obtained.

5. Fifth Preferred Example Extraction of Antimony and Silver by SmeltingStibnite, Stefanite and Tetrahedrite minerals concentrates.

In this process, the extraction of the Antimony metal from thesulphurated mineral that contains it is done by applying the directreduction improved with regeneration and recycling of the metallurgicalinputs involved, which is based on the proper use of both Iron (Fe) as areducing agent and Sodium Carbonate (Na₂CO₃) as a flux, and the productsof the chemical reaction between the reagents are the following: metalAntimony, a slag formed mainly by the insoluble compound Ferrous Oxide(FeO) and by the water-soluble compound Sodium Sulphide (Na₂S), and,gaseous emissions formed mainly by Carbon Dioxide (CO₂). In order toeffectively control the formation of the slag, the concentrated mineralsStibnite or Antimony Trisulphide (Sb₂S₃), which is a sulphurated mineralextracted from metal Antimony, should be inside the smelting furnace.Then, the reducing agent Iron (Fe) and the flux Sodium Carbonate(Na₂CO₃) are added to the reactor in stoichiometric proportions thatallow the regeneration and recycling of the mentioned metallurgicalinputs in the subsequent processes; for such purpose, the formation ofthe slag should be controlled, taking care that the latter isconstituted not by three or more compounds, but only by two, and one ofthem should be soluble in Water. In this regard, it should be pursuedthat the slag obtained from the smelting furnace during the metallicantimony extraction is only composed of Ferrous Oxide (FeO) and SodiumSulphide (Na₂S), which implies that the formation of Ferrous Sulphide(FeS) in the slag must be controlled, for which it is necessary for thereaction of the direct reduction process using Iron (Fe) as a reducingagent and Sodium Carbonate (Na₂CO₃) as a flux to be the following:

Sb₂S₃+3 Fe+3 Na₂CO₃→2Sb+3 Na₂S+3FeO+3 CO₂

In this case, chemical thermodynamics state that the reaction begins at300° C. and should preferably be completed at 625° C.

In view of the above, it is concluded that, in the direct reductionprocess of Antimony from the sulphurated mineral that contains it, thenumber of moles of Sodium Carbonate (Na2CO3), or its equivalent inweight, which must be considered as a reactant flux in the process, isdirectly related to the sulphur atoms existing in the chemical formulaof Stibnite or Antimony Trisulphide (Sb₂S₃), a mineralogical compoundcontaining the metal Antimony to be extracted. Likewise, the number ofgram-atoms of iron (Fe), or its equivalent in weight, which will need tobe considered as a reactive reducing agent in the process, is directlyrelated to the number of gram-moles of Ferrous Oxide (FeO) to beobtained as product and, since it depends on the number of gram-moles ofOxygen (O₂) released as such in the chemical reaction, it is concludedthat the required gram-atoms of Iron (Fe) atoms will depend on thenumber of moles of Sodium Carbonate (Na₂CO₃) considered as a flux andalso on the number of Sulphur atoms (S) contained in the concentratedmineral of Stibnite or Antimony Trisulphide (Sb₂S₃).

Regarding the extraction of Silver and Antimony from Stefanite(Ag₅SbS₄), the established procedure for non-ferrous sulphuratedminerals from two polyatomic metals is applied:

Ag₅SbS₄+4 Fe+4 Na₂CO₃→5 Ag+Sb+4 Na₂S+4 FeO+4 CO₂

Regarding the extraction of Antimony and Silver from the argentiferousTetrahedrite (Ag₃SbS₃+x(Fe, Zn)₆Sb₂S₉), considering for this case thatx=1 and that silver has replaced copper in the sulphosalt, theestablished procedure for combinations of ferrous and non-ferrousbimetallic sulphurated minerals:

[Ag₃SbS₃+(Fe, Zn)₆Sb₂S₉]+6 Fe+12 Na₂CO₃→→3 Ag+3 Sb++6 Zn+12 Na₂S+12FeO+12 CO₂

6. Sixth Preferred Example Extraction of Molybdenum by Smelting MineralMolybdenite Concentrates.

In this process, the extraction of molybdenum metal from the sulphuratedmineral that contains it (Molybdenite or MoS₂) is carried out byapplying the improved direct reduction process, which is based on theappropriate use of both iron (Fe) as a reducing agent and SodiumCarbonate (Na₂CO₃) as a flux, and the products of the chemical reactionbetween the reactants are the following: Powdered metallic molybdenumdue to its high smelting point, a light and fluid slag formed by FerrousOxide (FeO) and Sodium Sulphide (Na₂S), and gaseous emissions of CarbonDioxide (CO₂). Given its importance, during the aforementioned processof improved direct reduction, it is also necessary that there is aneffective control of the formation of the slag. For this purpose, oncethe concentrated minerals of Molybdenite are inside the smeltingfurnace, Iron (Fe) as a reducing agent and Sodium Carbonate (Na₂CO₃) asa flux are added, stating that the use of these metallurgical inputsmust be done in proper stoichiometric proportions, so that theregeneration and recycling of both the reducing agent and the flux ispossible from the products obtained from the chemical reaction. This canbe achieved if the slag is mainly formed not by three or more compounds,but only by two, and one of them should be soluble in Water. In thissense, it should be pursued that the slag obtained from the molybdenummetal extraction in the smelting furnace is only composed of theinsoluble compound Ferrous Oxide (FeO) and the water-soluble compoundSodium Sulphide (Na₂S), which implies that the non-formation of FerrousSulphide (FeS) in the slag must be controlled at the same time, forwhich the following chemical reaction is necessary in the main process:

MoS₂+2 Fe+2 Na₂CO₃→Mo+2 Na₂S+2 FeO+2 CO₂

In accordance with chemical thermodynamics, considering the energy costsinvolved, the reaction begins at 1175° C. and should preferably becompleted at 1375° C.

From the above, it is concluded that, during the process of directreduction of molybdenum from the sulphurated mineral that contains it,the number of moles of Sodium Carbonate (Na₂CO₃), or its equivalent inweight, which must be considered as a reactant flux, is directly relatedto the sulphur atoms in the chemical formula of molybdenite ormolybdenum disulphide (MoS₂). Likewise, the number of gram-atoms of Iron(Fe), or its equivalent in weight, which will need to be considered as areactive reducing agent in the process, is directly related to thenumber of gram-moles of Ferrous Oxide (FeO) that will be obtained as aproduct and, since it depends on the number of gram-moles of Oxygen (O₂)released as such in the chemical reaction, it is inferred that therequired gram-atoms of Iron (Fe) will depend on the number of moles ofSodium Carbonate (Na₂CO₃) considered as flux, and also on the number ofSulphur atoms (S) contained in the concentrated mineral Molybdenite orMolybdenite Bisulphide (MoS₂).

7. Seventh Preferred Example Extraction of Arsenic with Gold and/orArsenic with Silver by Smelting Arsenopyrite Auriferous and/or ProustiteConcentrates, Respectively.

During the extraction process of the Arsenic (As) and Gold (Au) metalscontained in the Gold Arsenopyrite (AsFeS with Au), we have thefollowing chemical reaction:

AsFeS+Au+Na₂CO₃→As+Au+Na₂S+FeO+CO₂

According to chemical thermodynamics, the previous reaction begins at825° C., and the reaction must be completed preferably at 1325° C.,considering reasonable energy costs.

When Gold Arsenopyrite is associated with Pyrite (FeS₂), the abovechemical reaction must be restated as follows:

AsFeS+Au+FeS₂+Fe+3 Na₂CO₃→As+Au+3 Na₂S+3 FeO+3 CO₂

According to chemical thermodynamics and considering the energy costs,the previous reaction begins at 770° C., and the reaction must becompleted preferably at 900° C.

Given that in certain cases the Gold Arsenopyrite is not only associatedwith Pyrite (FeS₂) but also with Chalcopyrite (CuFeS₂), thecorresponding chemical reaction is the following:

AsFeS+Au+FeS₂+CuFeS₂+2 Fe+5 Na₂CO₃→→As+Au+Cu+5 Na₂S+5 FeO+5 CO₂

According to chemical thermodynamics, the above reaction begins at 875°C., and it must be completed preferably at 975° C. consideringreasonable energy costs. It must have been verified that it is possibleto extract all the Arsenic contained in the aforementioned goldArsenopyrite concentrate at the most appropriate stoichiometricconditions and at a temperature of 1000° C.

Regarding the recovery of Gold, due to the relatively low boiling pointof the metal Arsenic, it is essential to consider the use of the metalLead as an additional reactant in the previous reactions, so that it canbe at the end the carrier of the Gold in the products of the reaction,not only because of the affinity that exists between the two metals, butalso because, together with Lead and Gold, they form a cast metalproduct of high specific weight, which is easily separated from the slagconstituted by sodium sulphide and ferrous oxide in order to obtain aproper casting.

Likewise, as in the previous preferred examples, in order to effectivelycontrol the formation of the slag, the chemical formulas established forArsenopyrite (AsFeS), Pyrite (FeS₂) and Chalcopyrite (CuFeS₂) are used,specifying that the smelting of the concentrates of these ferroussulphurated minerals together with the reducing agent Iron (Fe) and withthe flux Carbonate of Sodium (Na₂CO₃) should be carried out consideringthe appropriate stoichiometric amounts of the latter, not only so as toobtain a high recovery of Arsenic (As), Gold (Au) and Copper (Cu), asapplicable, but also to be able to reduce and recycle the reducing agentIron (Fe) and the flux Sodium Carbonate (Na₂CO₃) the subsequentprocesses, which implies that the slag from the extraction process ofArsenic (As) and Gold (Au) and/or Copper (Cu) should not be composed bythree or more compounds, but only by two, by Ferrous Oxide (FeO) andwater-soluble Sodium Sulphide (Na₂S), avoiding Ferrous Sulphide (FeS) asa component of the slag at all times. The third product of the abovechemical reactions is the gaseous effluents of Carbon Dioxide in thecorresponding stoichiometric amounts.

For the extraction process of the metals Arsenic (As) and Silver (Ag)contained in Proustite (AgAsS₃), the general referential chemicalreaction established for the non-ferrous sulphurated minerals of twopolyatomic metals is applied and, in this sense, the referred processhas the following chemical reaction:

Ag₃AsS₃+3 Fe+3 Na₂CO₃→3 Ag+As+3 Na₂S+3 FeO+3 CO₂

the technical criteria discussed above prevail for all purposes.

8. Eighth Preferred Example Iron Extraction by Smelting the Concentratesof Iron Sulphurated Minerals Such as Pyrrhotite, Pyrite and Marcasite.

During this extraction process of Iron (Fe) contained in sulphuratedminerals such as, without limitation, Pyrrhotite (FeS), Pyrite andMarcasite (both FeS₂), we use in an appropriate way both Iron (Fe) asfacilitator of the atomic exchange, if the stoichiometric balance of thechemical reaction requires it, as well as Sodium Carbonate (Na₂CO₃) as aflux, so that a slag that can be cast is obtained as a product of theprocess, which must have low density and low viscosity because it willbe formed by Ferrous Oxide (FeO) and Sodium Sulphide (Na₂S), giving alsothe respective gaseous emissions formed by Carbon Dioxide (CO₂) as asecond product. Likewise, in order to effectively control the formationof the slag, the chemical formulas established for iron sulphuratedminerals are used, such as Fe₂S in the case of Pyrites, specifying thatthe smelting of one gram-mole of Pyrite with a gram-atom of Iron (Fe)and one gram of the Sodium Carbonate (Na₂CO₃) flux must be madeconsidering the appropriate stoichiometric quantities in order to fullycontrol the composition of the slag to be produced, so that thereduction and recycling of both the sodium carbonate (Na₂CO₃) and theiron (Fe) flux that should be added, in the case of having irondisulphides as reactant, is possible in the subsequent processes. Thisimplies that care must be taken so that the slag from the Iron (Fe)extraction process is formed mainly not by three or more compounds, butonly by two, one of them should be soluble in Water (Sodium Sulphide),but not the other one (Ferrous Oxide), and also the formation of FerrousSulphide (FeS) in the slag should be avoided with the followingreaction:

FeS₂+Fe+2 Na₂CO₃ FeO+2 Na₂S+2 CO₂

According to chemical thermodynamics, the above reaction occurs at 750°C., and should preferably be completed at 950° C., consideringreasonable energy costs.

The control over the composition of the slag allows to take advantage ofthe high solubility of Sodium Sulphide (Na₂S) in Water (H₂O) and, forthe purposes of having the Ferrous Oxide (FeO) compound as the onlysolid residue, it is indispensable that the slag, which is obtained inthe smelting furnace for iron sulphide concentrates, is mixed in theSolution reactor with the amount of liquid water necessary, consideringthe solubility of Sodium Sulphide (Na₂S), so that the followingelectrochemical dissociation reaction occurs:

Na₂S+H₂O⇄2 Na⁺+HS⁻+OH⁻

Then, the resulting solution is filtered, and only solid waste formed byFerrous Oxide (FeO) is separated. Next, the agglomeration and subsequentsintering of the solid waste is carried out in the respective furnace,at a controlled temperature, so that the agglomerated Ferrous Oxide(FeO) products, appropriately sintered and converted into “pellets”,acquire the mechanical property of compressive resistance requiredinside the Iron Reduction Furnace, where the FeO “pellets” will befinally sent. In order to achieve the reduction of the iron contained inFerrous Oxide “pellets”, it is necessary to have coal, metallurgicalcoke or natural gas fuel available in the combustion furnace, where thereducing gases (carbon monoxide and hydrogen) will be generated, andinsufflate them both with air and/or water vapor required as the casemay be, such as the gaseous effluents Carbon Dioxide (residual CO₂) andCarbon Monoxide (remaining CO) recycled from the Iron Reduction Furnace,which result in the following chemical reactions at a temperaturebetween 900° C. and 1000° C., as applicable:

C+CO₂→CO₂

C+CO₂→2 CO

C+H₂O→CO+H₂

C+2 H₂O→CO₂+2 H₂

CO+H₂O→CO₂+H₂

CH₄+H₂O→3 H₂+CO

The sintered “pellets” are introduced and accumulated in the IronReduction Furnace in order to be subjected, for the necessary period, tothe appropriate flow of the Carbon Monoxide (CO) and Hydrogen (H₂)reducing gases from the combustion furnace, which causes the oxidationstate +2 of Iron to be reduced to zero, thus making possible theextraction of metal iron (Fe) using the following chemical reactions:

FeO+CO→Fe+CO₂

FeO+H₂→Fe+H₂O

From the above, it is concluded that, in a process of Iron extractionfrom Pyrite and Marcasite (both Iron Bisulphides: FeS₂), Pyrrhotite(Iron Sulphide: FeS) or other Iron

Sulphides, the number of gram-atoms of iron (Fe), or its equivalent inweight, which will have to be considered as a reactant in the process,is directly related to the number of atoms of sulphur (S) contained inPyrite and/or Marcasite (FeS₂), with the exception that the gram-atomsof Iron, or its equivalent in weight, that are contained in the Pyriteand/or Marcasite to be cast must be deducted in this calculation. And,on the other hand, the number of moles of Sodium Carbonate (Na₂CO₃), orits equivalent in weight, which must be considered as a reactant flux inthe Iron extraction process, is also directly related to the amount ofSulphur atoms existing in the chemical formula of Pyrite and/orMarcasite (Iron Bisulphides: FeS₂). It is specified that, in the casethat the cast of one mole gram of Pirotite (FeS) is desired, only onemole gram of sodium carbonate will be required as a flux. It isnecessary to consider the previous indications so as to have controlover the composition of the slag, which must be composed of FerrousOxide (FeO) and Sodium Sulphide (Na₂S). Gaseous emissions of CarbonDioxide (CO₂) will be obtained as an additional product in these cases.As previously mentioned, an adequate control over the composition of theslag makes it possible to take advantage of the high solubility ofSodium Sulphide in Water, which, in turn, makes it possible to obtainFerrous Oxide (FeO) as the only solid residue after the correspondingfiltering, which will then be agglomerated and sintered to obtain“pellets” of Ferrous Oxide. The metal Iron, which was to be extractedfrom the Iron sulphurated minerals, is obtained from this pellets.

REFERENCES:

-   (1) Aranguren F. & Mallol A. (1963).Siderurgia, Madrid, Editorial    Dossat.-   (2) Aranguren F. & Mallol A. (1963).-   (3) Aranguren F. & Mallol A. (1963).-   (4) Bray J. (1968). Metalurgia Extractiva de los Metales o Férreos,    Madrid. Ediciones Interciencia.-   (5) Aranguren F. & Mallol A. (1963).-   (6) Zambrano C. (1988). Apoyo a la puesta en marcha de la Planta de    Carbonato de Sodio en solución de Química del Pacífico S.A. Informe    de Prácticas. Facultad de Química e Ingeniería Qúimica de la    Universidad Nacional Mayor de San Marcos.-   (7) Choppin G. & Jaffe B. (1970).-   (8) Costa A. (1955). Breve estudio sobre la posibilidad de instalar    una Planta de Carbonato de Sodio en el Perú. Tesis de Grado para    optar el título de Ingeniero Químico por la Universidad Nacional    Mayor de San Marcos, Lima.-   (9) Fung C. & Luján R. (1978). Proyecto para la Instalación de una    Planta de Carbonato de Sodio en Química del Pacífico S.A. Informe de    Prácticas en la Escuela Académico Profesional de Ingeniería Química.    Facultad de Química e Ingeniería Química. Universidad Nacional Mayor    de San Marcos, Lima.-   (10) Zambrano C. (1988).

1-12. (canceled)
 13. A process for the continuous extraction of metalsfrom sulphurated minerals containing them, with or without associatediron, characterized by the direct reduction of the specific metal ormetals to be extracted, with regeneration and recycling of iron asreducing agent, and sodium carbonate as flux, from slag and liquid andgaseous effluents derived from processes involved, in which said processincludes the following steps: Extraction of metals in the smeltingfurnace that smelts ferrous and/or non ferrous concentrated sulphuratedminerals containing the metal to be extracted, including, but notlimited to, lead, silver, zinc, copper, molybdenum, antimony, arsenic,with or without iron associated and, with gold and silver inclusion incertain cases, using iron as a reducing agent of said non-ferrous metalsand sodium carbonate as a flux; resulting in molten or powdery metalsextracted, a controlled smooth slag consisting of ferrous oxide andsodium sulphide, and gaseous emissions of carbon dioxide. Selectivedissolution in water of sodium sulphide from slag and filtering of wastein order to obtain two intermediate products, the solid ferrous oxideand a filtered sodium sulphide solution. Regeneration of sodiumcarbonate in solution reactor for recycling, by mixing the filteredsodium sulphide solution with an over-saturated sodium carbonatesolution. The gaseous effluent carbon dioxide is captured and recycledfrom the non-ferrous metal extraction process by direct reduction, andblown to the above mixture, which results in regenerated sodiumcarbonate, and hydrogen sulphide gas and water, as intermediateproducts. Removing hydrogen sulphide gas and obtaining sulphur, bycapturing and conducting the gaseous effluent to a solid/gas reactor, sothat it reacts with the hydrated iron oxide to obtain ferric sulphideand water. With proper ventilation, these products are converted intoelemental sulphur and water, and regenerated hydrated iron oxide forrecycling. Ferrous oxide sintering, by previous agglomeration andsubsequent heating of solid waste, obtained by filtration, at acontrolled temperature between 1100 and 1300° C., then some slag isdissolved to obtain ferrous oxide pellets with compression strength, aphysical property required in the next stage of regeneration of thereducing agent, iron. Generation of reducing gases, carbon monoxide andhydrogen, obtained in a combustion furnace, by using coal, metallurgicalcoke or natural gas as fuel. The necessary air and water vapor are blownto said furnace where the process is carried out. Recycled gases such asresidual carbon dioxide and remaining carbon monoxide are also blown.These gases are taken from the reducing furnace in which the reducingagent, iron, is regenerated. Regeneration of iron as reducing agent forrecycling by reducing said metal contained in ferrous oxide. Thisresidue was derived from the dissolution of slag that has beenagglomerated and sintered for a proper reaction with the reducing gases,carbon monoxide and hydrogen, generated in the combustion furnace. Metaliron was then obtained and recycled in the smelting furnace ofconcentrated sulphurated mineral concentrates.
 14. A method forextracting base and precious metals from ferrous and/or non-ferroussulphurated minerals containing them, characterized by smelting metal ormetals to be extracted in concentrate form, including, but not limitedto, lead, silver, zinc, copper, molybdenum, antimony, arsenic, includinggold and/or silver if they occur as inclusions in pyrite, arsenopyrite,chalcopyrite, using iron as a reducing agent and sodium carbonate asflux, resulting in metal or metals extracted, molten or in powdery solidstate, a controlled, smooth slag consisting of ferrous oxide and sodiumsulphide, and gaseous emissions of carbon dioxide.
 15. A process forobtaining metallic iron from the processing of slag consisting offerrous oxide and sodium sulphide, characterized by: Dissolving sodiumsulphide, a slag compound, in water. Filtering ferrous oxide from solidwaste. Agglomerating and sintering ferrous oxide for pellet formation ofthis compound. Generating reducing gases, carbon monoxide and/orhydrogen, obtained in a combustion furnace, by using coal, metallurgicalcoke or natural gas, together with oxygen, water vapor and/or carbondioxide. Optionally, this particular step may be dispensed with,provided that the reducing gases, carbon monoxide and/or hydrogen,instead of being generated, are acquired. Reducing iron contained inferrous oxide pellets using carbon monoxide and/or hydrogen gases asreducing agents.
 16. A process for obtaining sodium carbonate fromcarbon dioxide gas and smelting slag consisting of ferrous oxide andsodium sulphide, characterized by: Dissolving sodium sulphide, a slagcompound, in water. Filtering and separating the solution resulting fromthe dissolution of sodium sulphide in water. Processing the filteredsodium sulphide solution with carbon dioxide gas and an over-saturatedsodium carbonate solution. Filtering and heating the resulting sodiumbicarbonate crystals for conversion into sodium carbonate crystals.Removing sulphurated hydrogen gas, generated in the processing of thefiltered sodium sulphide solution, in order to make it react in asolid/gas reactor with hydrated iron oxide crystals. Obtaining ferricsulphide crystals and water in the solid/gas reactor. Ventilating ferricsulphide crystals and water in order to regenerate hydrated iron oxidefor recycling and, at the same time, to produce elemental sulphur andwater.
 17. A method according to claim 14, for extracting gold andsilver, occurring as inclusions in iron sulphurated minerals, and/orsilver contained in their sulphides, characterized by smelting mineralconcentrates, including, but not limited to, arsenopyrite, pyrite,marcasite, pyrrotite, chalcopyrite, argentite or acantite, using sodiumcarbonate as a flux, iron as a reducing agent where applicable and, asan additional aggregate, together with reactants, metallic lead, goldand silver carrier in the final product obtained from the extraction ofthe above precious metals.
 18. A process for extracting metallic ironfrom concentrated sulphurated minerals of iron, including, but notlimited to, pyrrotite and arsenopyrite monosulphides, marcasite andpyrite bisulphides, characterized by smelting these concentrates usingsodium carbonate as a flux, and additional iron as a reducing agentwhere applicable, resulting in the extraction of metallic iron from theslag generated, which consists of ferrous oxide and sodium sulphide.Said metallurgical inputs are regenerated and recycled by taking thefollowing steps: Smelting iron concentrated sulphurated minerals, usingsodium carbonate as a flux and additional iron as a reducer or reactantwhere applicable. Dissolving sodium sulphide, a slag compound, in water.Filtering ferrous oxide from solid waste. Agglomerating and sinteringferrous oxide for pellet formation of this compound. Generating reducinggases, carbon monoxide and hydrogen, obtained in a combustion furnace,by using coal, metallurgical coke or natural gas, together with oxygen,water vapor and/or carbon dioxide. This step may be dispensed with ifthe reducing gases, carbon monoxide and/or hydrogen, are acquired.Reducing iron contained in ferrous oxide pellets using carbon monoxideand/or hydrogen gases as reducing agents.
 19. A process for the directreduction of metals from ferrous and non-ferrous concentratedsulphurated minerals containing them, according to claim 13,characterized by controlling the slag composition, which enablesregeneration and recycling of the reducing agent and flux, bydetermining the necessary amounts of iron (reducing agent) and sodiumcarbonate (flux) required for the process through the following generalreaction for single-metal non-ferrous sulphurated minerals:M_(x)S_(y)+y Fe+y Na₂CO₃→x M+y Na₂S+y FeO+y CO₂ Where: M is thenon-ferrous metal to be extracted including, but not limited to, lead,silver, zinc, copper, molybdenum, antimony. MxSy is the chemical formulaestablished for the sulphide mineral from which metal M is to beextracted. x and y indicate the number of atoms of sulphur and metal Mto be extracted, respectively, from MxSy; the stoichiometriccoefficients of the remaining reactants and those of the productsobtained in the process, depend on its values.
 20. A process for thedirect reduction of metals from ferrous and non-ferrous concentratedsulphurated minerals containing them, according to claim 13,characterized by controlling the slag composition, which enablesregeneration and recycling of the reducing agent and flux, bydetermining the necessary amounts of iron (reducing agent) and sodiumcarbonate (flux) required for the process through the following generalreaction for single-metal ferrous sulphurated minerals:M_(x)Fe_(y)S_(z)+(z−y)Fe+z Na₂CO₃→x M+z Na₂S+z FeO+z CO₂ Where: M is thenon-ferrous metal to be extracted including, but not limited to, copper,arsenic, lead, zinc. MxFeySz is the chemical formula established for theferrous sulphide mineral from which metal M is to be extracted. x, y, zindicate the number of atoms of iron, sulphur and metal M to beextracted, respectively, from MxFeySz; the stoichiometric coefficientsof the remaining reactants and those of the products obtained in theprocess, depend on its values.
 21. A process for the direct reduction ofmetals from ferrous and non-ferrous concentrated sulphurated mineralscontaining them, according to claim 13, characterized by controlling theslag composition, which enables regeneration and recycling of thereducing agent and flux, by determining the necessary amounts of iron(reducing agent) and sodium carbonate (flux) required for the processthrough the following general reaction for ferrous and/or non ferroussulphurated minerals of single metal, with gold and/or silver.M_(x)Fe_(y)S_(z)+(Au,Ag)_(m)+n Pb+(z−y)Fe+z Na₂CO₃→→x M+m(Au,Ag)+n Pb+zNa₂S+z FeO+z CO₂ Where: M is the non-ferrous metal to be extracted,including, but not limited to copper, arsenic, lead, zinc. MxFeySz isthe chemical formula established for ferrous and non-ferrous sulphidemineral (for y=0) from which the associated M metal and precious metalsare to be extracted. x, y, z indicate the number of atoms of iron,sulphur and metal M to be extracted, respectively, from MxFeySz, thestoichiometric coefficients of the remaining reactants and those of theproducts obtained in the process, depend on its values. (Au,Ag)mrepresents the inclusions of gold (Au), silver (Ag) and electrum (Au/Ag)that are presented under number “m” within the MxFeySz mineral matrix.Pb represents the metal Lead which in the amount “n” is added togetherwith reactants to be the final carrier of Gold and Silver.
 22. A processfor the direct reduction of metals from ferrous and non-ferrousconcentrated sulphurated minerals containing them, according to claim13, characterized by controlling the slag composition, which enablesregeneration and recycling of the reducing agent and flux, bydetermining the necessary amounts of iron (reducing agent) and sodiumcarbonate (flux) required for the process through the following generalreaction for combinations of several ferrous and/or non ferroussulphurated minerals of a single metal.[(M1)_(a)Fe_(b)S_(c)+(c−b)Fe+c Na₂CO₃]+[(M2)_(x)Fe_(y)S_(z)+(z−y)Fe+zNa₂CO₃]→→a (M1)+x (M2)+(c+z)Na₂S+(c+z)FeO+(c+z)CO₂ which expressedotherwise is equal to:(M1)_(a)Fe_(b)S_(c)+(M2)_(x)Fe_(y)S_(z)+[(c−b)+(z−y)]Fe+(c+z) Na₂CO₃→→a(M1)+x (M2)+(c+z) Na₂S+(c+z) FeO+(c+z) CO₂ Where: M1 and M2 are thenon-ferrous metals to be extracted, including, but not limited tocopper, arsenic. (M1)aFebSc and (M2)xFeySz are the chemical formulasestablished for ferrous and/or non-ferrous sulphurated minerals (for y=0), from which non-ferrous metals M1 and M2 are to be extracted.Subscripts a, b, c as well as x, y, z indicate the number of atoms ofmetals M1 and M2, Iron and Sulphur in (M1)aFebSc and (M2)xFeySz. Thestoichiometric coefficients of the remaining reactants (reducing agentand flux) and those of the products obtained in the process (moltenmetals, slag, and gaseous effluent), depend on its values.
 23. A processfor the direct reduction of metals from ferrous and non-ferrousconcentrated sulphurated minerals containing them, according to claim13, characterized by controlling the slag composition, which enablesregeneration and recycling of the reducing agent and flux, bydetermining the necessary amounts of iron (reducing agent) and sodiumcarbonate (flux) required for the process through the following generalreaction for ferrous and/or non-ferrous bimetallic sulphurated minerals.(M1)_(a)(M2)_(b)Fe_(y)S_(z)+(z−y) Fe+z Na₂CO₃→a(M1) b(M2)+z Na₂S+z FeO+zCO₂ Where: M1 and M2 are the non-ferrous metals to be extracted,including, but not limited to, antimony, zinc, copper, silver, arsenic,cobalt. (M1)a(M2)bFeySz is the chemical formula established for ferrousand/or non ferrous sulphide mineral (for y=0), from which non-ferrousmetals M1 and M2 are to be extracted. Subscripts a, b as well as y, zindicate the number of atoms of metals M1 and M2 such as iron andsulphur, respectively, in (M1)a(M2)bFeySz. The stoichiometriccoefficients of the remaining reactants (reducing agent and flux) andthose of the products obtained in the process (molten metals, slag, andgaseous effluent), depend on its values.
 24. A process for the directreduction of metals from ferrous and non-ferrous concentratedsulphurated minerals containing them, according to claim 13,characterized by controlling the slag composition, which enablesregeneration and recycling of the reducing agent and flux, bydetermining the necessary amounts of iron (reducing agent) and sodiumcarbonate (flux) required for the process through the following generalreaction for ferrous and non-ferrous bimetallic sulphurated mineralscombinations:[(M1)_(a)(M2)_(b)Fe_(c)S_(d)+(M3)_(w)(M4)_(x)Fe_(y)S_(z)+[(d−c)+(z−y)]Fe+(d+z)Na₂CO₃]→→a (M1)+b (M2)+w (M3) x (M4)+(d+z) Na₂S+(d+z) FeO+(d+z) CO₂Where: M1, M2, M3 and M4 are the non-ferrous metals to be extracted,including, but not limited to, antimony, zinc, copper, silver, arsenic,cobalt. (M1)a(M2)bFecSd and (M3)w(M4)xFeySz are the chemical formulasestablished for ferrous and non-ferrous sulphurated minerals, from whichnon-ferrous metals M1, M2, M3 and M4 are to be extracted. Subscripts a,b, c, d as well as w, x, y, z indicate the number of atoms of metals M1,M2, M3 and M4, Iron and Sulphur, respectively, in (M1)a(M2)bFecSd and(M3)w(M4)xFeySz. The stoichiometric coefficients of the remainingreactants (reducing agent and flux) and those of the products obtainedin the process (molten metals, slag, and gaseous effluent), depend onits values. Note that the above stoichiometric formulation is valid evenwhen any (or all) of the following cases are present: When the chemicalformulas of bimetallic sulphurated minerals have a non-ferrous metal incommon; i.e. when (M1, M2) is equal in part to (M3, M4). When in thecombination of bimetallic sulphurated minerals, one of the sulphuratedminerals is ferrous and the other sulphide mineral is non-ferrous. Inthis regard, the simultaneous occurrence of both cases above would havethe following stoichiometric formulation, where M4=M2 and y=0:[(M1)_(a)(M2)_(b)Fe_(c)S_(d)+(M3)_(w)(M2)_(x)S_(z)[(d−c)+(z)]Fe+(d+z)Na₂CO₃]→→a(M1)+(b+x)(M2)+w(M3)+(d+z)Na₂S+(d+z)FeO+(d+z)CO₂